Is it just me, or do you experience this too? When I hear the words "ark of the covenant," I picture melting zombies from the movie Raiders of the Lost Ark (Indiana Jones):
It's a great scene but obviously fiction. In reality, the ark of the covenant held the stone tablets with the 10 commandments. The Israelites kept the ark in the tabernacle, which was a tent that was set up in the middle of their camp. It's where God resided because he always wanted to live among His people.
The ark of the covenant is actually the beginning of the Bible's formation. Moses wrote scrolls which were kept with the ark and those documents would eventually be included in what we now call the "Old Testament."
It may seem strange that God was so specific about the dimensions of the tabernacle and the ark but it's for good reason: God wanted the Israelites to pay close attention, and every detail is symbolic of a bigger truth.
And finally, if you have a couple minutes, here's that Raiders of the Lost Ark scene: